He orders officials to ignore the previous president's written assertions that raised constitutional objections to legislation. Obama says he will limit his own use of such statements.

WASHINGTON — In another effort to undo acts by the previous administration, President Obama instructed executive branch officials Monday to check with the Justice Department before enforcing former President George W. Bush's signing statements, the written assertions presidents sometimes make when signing bills that may raise constitutional questions.

At the same time, Obama spelled out in a memo the guidelines he would follow in issuing his own signing statements. Bush-era statements that failed to comply with Obama's guidelines would be disregarded.

He signaled that, unlike Bush, he would not use signing statements to do end runs around Congress.

According to one count, Bush issued 161 signing statements in which he cast doubt on more than 1,000 provisions in legislation and essentially stated his intention to ignore those parts of the law.

Former President Clinton issued significantly more signing statements, but Bush was more aggressive in making claims that the legislation in question would undermine presidential authority.

Bush's signing statements were viewed by many critics, Republican and Democratic alike, as another attempt to expand the scope of presidential power. Bush didn't publicize them, however, and for much of his presidency, the public was largely unaware of this practice.

Obama's memo was a renunciation of the practice, which he had criticized during the presidential campaign.

"In recent years, there has been considerable public discussion and criticism of the use of signing statements to raise constitutional objections to statutory provisions," Obama's memo said. "There is no doubt that the practice of issuing such statements can be abused.

"Constitutional signing statements should not be used to suggest that the president will disregard statutory requirements on the basis of policy disagreements," the memo continued.

Obama acknowledged, however, that a president could legitimately use signing statements. He said he would work with Congress to limit his use of such statements and would specify his constitutional objections to legislation to ensure greater transparency.

As for Bush-era directives, he said: "To ensure that all signing statements previously issued are followed only when consistent with these principles, executive branch departments and agencies are directed to seek the advice of the attorney general before relying on signing statements issued prior to the date of this memorandum as the basis for disregarding, or otherwise refusing to comply with, any provision of a statute," Obama's memo said.